| As organic chemicals are widely used in industrial production and life,th e leakage of organic chemicals,excessive use can cause it into the soil and gr oundwater environment,thus caused to the groundwater and soil pollution,espe cially chlorinated hydrocarbon and aromatic hydrocarbon detection is more pro minent in the contaminated sites,therefore,to study the medium of groundwate r environment for chlorinated hydrocarbon adsorption of aromatics in contamina ted sites to the repair has important guiding significance.In this paper,two repr esentative organic compounds of aromatic hydrocarbons(toluene and benzene)and two representative organic compounds of chlorinated hydrocarbons(1,2,3-trichloropropane and 1,2-dichloropropane)were selected as the target pollutants.The adsorption characteristics of each target pollutant in the groundwater envir onment medium were studied by static adsorption batch experiment.The main conclusions are as follows:(1)through the static adsorption batch experiment found that in a typical aquifer medium fine sand in the benzene series of aromatic hydrocarbon conten t compared with chlorinated hydrocarbon faster to reach adsorption equilibrium,and the four goal pollutant adsorption medium adsorption are given priority to with linear adsorption,the adsorption process conforms to Henry model,four kinds of pollutants adsorption intensity order: toluene > benzene > 1,2-> 1,2,3-dichloro propane cross-linked with propane;(2)through static adsorption batch experiments,it was found that the co mpetitive adsorption of benzene and toluene on fine sand medium was also inf luenced by the two mechanisms of surface point competition and distribution.Benzene promoted the adsorption of toluene on fine sand medium,and toluene inhibited the adsorption of benzene on fine sand medium.The competitive ads orption of 1,2-dichloropropane and TCP on fine sand medium mainly lies in t he competition of the point position on the surface of the medium,which has little influence on the distribution.1,2-dichloropropane obviously inhibits the a dsorption of TCP on fine sand medium,while trichloropropane has no obvious effect on the adsorption of 1,2-dichloropropane.(3)through static adsorption batch experiments,it was found that the ads orption capacity of TCP on aquifer increased with the increase of benzene con centration.Chlorinated hydrocarbon of toluene adsorption effect can be divided i nto two kinds of circumstances,when the initial concentration is low(< 2 mg/L),toluene adsorption quantity increases with the increase of chlorinated hydro carbon concentration,when the initial concentration of toluene(2 mg/L)or hig her,toluene adsorption was increased with the increase of chlorinated hydrocar bon concentration decreased,namely chlorinated hydrocarbon of relatively high concentration of benzene content in the aquifer medium has inhibitory effect o n the absorption;(4)through experiments,it is found that the adsorption performance of si lt medium on chlorinated hydrocarbons aromatic hydrocarbons is better than tha t of coarse sands medium.The main reason is that the surface area of silt me dium is larger than that of coarse sands,while the adsorption of chlorinated h ydrocarbons aromatic hydrocarbons is mainly based on surface adsorption with weak distributive effect.In the competitive adsorption system of toluene and b enzene,the adsorption effect of powder sand on toluene is greater than that of benzene.In the competitive system of TCP and 1,2-dichloropropane,the adso rption effect of powder sand on TCP is more obvious than that of 1,2-dichlor opropane.The removal of organic matter is equivalent to providing more adsorp tion points for organic pollutants,that is,the adsorption performance of natural fine sand is improved after the removal of organic matter,and the increase is also in line with the law of competitive adsorption in chapter iii.Two clay mi neral kaolinite and montmorillonite is also suppresses the natural sand adsorptio n of chlorinated hydrocarbons aromatic hydrocarbon,but its inhibition principle is different,clay mineral adsorption process itself is through the interlayer rel ative organic matter on adsorption,adsorption and clay mineral surface charge will combine with natural sand reduce adsorption point,then reduce the adsorp tion performance,reduces the law is just the reverse of competition adsorption rule,namely the pollutant adsorption capacity,the greater the competition in t he added montmorillonite adsorption ability of the fine sand medium. |
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